丝尾鳠生物学特性及人工养殖技术

目的探讨植物蛋白替代鱼粉对丝尾鳠(Hemibagrus wyckioides)生长及生理的负面影响，以及饲料中添加精氨酸(Arg)对负面影响的缓和作用。方法随机选取375尾体重为(6.40±0.06) g的健康丝尾鳠幼鱼，随机分为5组，分别饲喂全鱼粉(FM组)、替代25%鱼粉(25% I组)、替代25%鱼粉+1.5% Arg (25% II组)、替代50%鱼粉(50% I组)和替代50%鱼粉+1.5% Arg (50% II组)饲料，饲喂8周，测定各处理组试验鱼的生长性能。饲养结束后，用试剂盒（南京建成）和石蜡切片法分别测定血液生化指标及肠道组织结构。结果50% I组丝尾鳠的特定生长率(SGR)和鱼体粗蛋白含量最低，且显著低于FM组(P<0.05)；50% I组料肉比(FCR)最高，且显著高于FM组(P<0.05)；25% I和50% I组丝尾鳠血液尿素氮(UN)显著高于FM组(P<0.05)。随着饲料中鱼粉替代比例的增加，丝尾鳠生长性能和体蛋白沉积随之降低，而血液尿素氮水平升高。通过Arg介导后，50% II组丝尾鳠生长和生化指标与FM组无显著差异(P>0.05)。肠道形态学结果显示：25% I、50% I和50% II组丝尾鳠的中肠绒毛高度(HV)显著小于FM组(P<0.05)；50% I组丝尾鳠的中肠绒毛宽度(WV)显著低于FM、25% I和25% II组(P<0.05)；50% I和50% II组杯状细胞个数(GC)显著多于FM、25% I和25% II组(P<0.05)；5组丝尾鳠中肠肠道整体的完整和健康程度评价为：FM≥25% II≥25% I >50% II >50% I。结论植物蛋白替代50%以上的鱼粉会对丝尾鳠生长、生理生化和肠道健康产生一定的负面影响，其最适替代量为25%~50%。通过添加1.5% Arg可以缓解植物蛋白对生长的抑制作用，并有助于修复肠道健康。

Dietary protein requirement of juvenile Asian red-tailed catfish Hemibagrus wyckioides

Purprose We investigated the impact of replacing fish meal with plant-based protein on the growth and physiology in Hemibagrus wyckioides, and the rescuing effect of Arg on them.MethodA total of 375 healthy juvenile H. wyckioides (initial weight 6.40 g±0.06 g) were randomized to five equal groups with 3 replicates, which were fed five diets containing whole fish meal (FM group), replacing 25% fish meal (25% I group), replacing 25% fish meal + 1.5% Arg (25% II group), replacing 50% fish meal (50% I group), replacing 50% fish meal + 1.5% Arg (50% II group), respectively. The growth performance of each group was measured during the 8 weeks feeding trial. After the rearing test, the blood biochemical index and intestinal tissue structure of experimental fish in each treatment group were measured using Kit (Nanjing jiancheng) and paraffin section method, respectively.ResultAmong the five diet groups, the specific growth rate (SGR) and crude protein content of H. wyckioides in 50% I group were lowest, significantly lower than FM group (P<0.05). While, the feed conversion ratio (FCR) in 50% I group was highest, significantly higher than FM group (P<0.05). Meanwhile, the blood urea nitrogen (UN) of H. wyckioides in 25% I and 50% I groups were higher than FM group (P<0.05). Those result suggested that the growth performance and body protein deposition of H. wyckioides was decreased and the level of blood urea nitrogen was increased with increasing replacement ratio. After the Arg-mediated, the growth and biochemical indicators of H. wyckioides in 50% II group showed no significant difference with those in FM group (P>0.05). Intestinal morphology analysis indicated that the midgut villus height of H. wyckioides in 25% I, 50% I and 50% II groups were significantly lower than FM group, respectively (P<0.05). The midgut villus width of H. wyckioides in 50% I group was significantly lower than 25% I, 25% II and FM groups (P<0.05). A higher number of goblet cells in 50% I and 50% II groups were observed among the five groups (P<0.05). The integrity and health of the midgut of H. wyckioides in five experimental groups were evaluated as follows: FM≥25% II≥25% I > 50% II > 50% I.ConclusionIt has a negative effect on growth, physiological and biochemical and intestinal health of H. wyckioides, when plant protein replaces more than 50% of fish meal. The optimal substitution quantity of replacing fish meal with plant-based protein is 25%~50%. Addition of 1.5% Arg can alleviate the inhibition of plant proteins on growth and help to repair intestinal health.